Fluid mixer



L. w. YOUNG Oct. 12, 1937.

I FLUID MIXER Filed June 9, 1934 lNVEN'i'OR LLOYD w. YOUNG ATTORNEYPatented Oct. 12, 1937 FLUID MIXER Lloyd W. Young, Elizabeth, N. J.,assignor, by mesne assignments, to Union Carbide and -OarbonCorporation, a corporation of New Application June 9, 1934, Serial No.729,777

3 Claims;

This invention relates to a 'fiuid mixer and more particularly to animproved gas mixer for blowpipes which is especially adapted for firstmixing air with a fuel gas, such as acetylene, and then mixing suchacetylene-air mixture with substantially pure oxygen to provide-anacetylene-air-oxygen combustible mixture capable of producing a weldingor preheating flame.

In some classes of welding and high-temperature heating operations it isdesirable to reduce the volume of the fuel gas used, in order to performthe operation more economically. The main object of this invention is toprovide a gas 'mixer for this purpose whereby such fuel gas may be firstsatisfactorily and conveniently diluted with atmospheric air, afterwhich substantially pure oxygen maybe thoroughly mixed with theso-diluted fuel gas. Other objects of the invention are to provide agasmixer of this character which is simple and compact; has a minimum ofmovable elements; is readily accessible for repair or repiacement; andwill be applicable to known blowpipe constructions without much changein the latter. The above and other objects and the novel features of theinvention will become apparent from the following description and theaccompanying drawing which illustrates one embodiment of the inventionand in which:

. Fig. 1 is a longitudinal mid-section of a blowpipe embodying theinvention; and

Fig. 2 is a partial cross-section on the line II-II' of Fig. 1.

In the embodiment of the invention illustrated in the drawing there isshown a blowpipe head 1-! which is in generaloi known construction. Thisbody or head I-I may be unitary; that is to say it may be made entirelyof one piece as illustrated in the drawing. Conduits It], H and ii for afuel gas such as acetylene, for heating oxygen and for cutting oxygen,respectively, connect with the rear end of the blowpipe head H in knownmanner, and the flow of gas through each conduit may be controlled byany preferred or usual valve arrangement (not shown).

There is also provided at the rear end of the blowpipe head H animproved mixer M to which the acetylene, the diluting air, and theheating oxygen are supplied. This construction and arrangement will bedescribed later.

The forward end of the blowpipe head H is shown as turned at an angleand is counterbored to provide a cavity 0 to receive the usual nozzle N.At the inner extremity of the cavity C there is a face 53 against whichthe rear face of the nozzle N is pressed by means of a cou pling nut l4having an external thread 55 which screws into an internal thread it inthe cavity C for securing the nozzle N to the blowpipe head H, in Wellknown manner. The outlet of a duct ll through the blowpipe head I-Iregisters with the inlet of a central duct is in the nozzle N andcarries cutting oxygen from the cutting oxygen conduit E2 to the nozzle.A heating gas duct E9 in the blowpipe .head H connects the outlet end ofthe mixer M with an annular recess 29 in the inner face it of the cavityC; and the inner ends of ducts 25 in the nozzle N register with theannular recess 2? in every position of the nozzle when coupled to theblowpipe head. The ducts 2i carry the combustible mixture to the outerend of the nozzle N.

The mixer M comprises a bore 22 in the blowpipe head H; a communicatingmixer throat 23 extending from the inner end of the bore 22 to theheating gas duct l9; and a mixer nozzle 24 disposed in the bore 22substantially axially thereof with its inner end adjacent but spacedfrom the entrance to the mixer throat 23. The mixer nozzle 2t ispreferably unitary or formed in a single pieceas shown in Fig. 1. Thenozzle 24 and the blowpipe head H form between them two annular chambers25 and 255 in the bore 22. The nozzle 24 has a threaded section 2'!intermediate its ends which screws into a corresponding threaded sectionin the bore thereby securing the nozzle fi l in position and separatingthe chambers 25 and 26. The threaded section 2''! of the nozzle 2% isformed with the roots of the threads therein no deeper than theunthreaded circumferential surfaces of the nozzle adjacent thereto, andthe crests of the threads extend outwardly therebeyond. Thus, when thenozzle has been screwed into place an annular chamber may be formed oneither side of the threaded sectionjbetween the nozzle and the innersurfaces of the bore in the blowpipe head H.

The nozzle 24 has a conical tip 28 adjacent the mixer throat 23, and aneck 29 of reduced section connects the tip to the body portion of thenozzle. A. central passage 39 in the nozzle extends substantiallyaxially through a part of the body portion, through the neck 29, throughthe tip 28, and has its outlet opposite the entrance of the throat 23. Aconnecting passage 3! extends between the central passage 36, throughthe unthreaded section of the nozzle body behind the threads 21, intothe rear chamber 26. A duct 32 connects the chamber 26 with the heatingoxygen conduit II. Thus heating oxygen may flow through the duct 32 intothe chamber 26, thence through the connecting passage 3! to the centralpassage 30.

An acetylene duct 33 connects the acetylene conduit l!) with the frontchamber 25.

Air for diluting the acetylene may be supplied directly from theatmosphere to the front chamber 25. For this purpose the mixer nozzle 2dmay be provided with a plurality of eccentric passages 34 which extendlongitudinally of the nozzle body, from its extreme outer end to thecircumferential recess 29' around the neck 29. The inlets of thepassages 34 are thus open to the atmosphere and their outlets terminatein the recess 29 which communicates directly with the chamber 25.

The outer end of the mixer nozzle Ed has a head 35 provided on its underside with a suitable annular sealing surface 36 to cooperate and providea gas-tight fit with a corresponding sealing surface 3'! at the mouth ofthe bore 22. The periphery of the head 35 may have a hexagon or othersuitable shape to fit a wrench for removing or tightly inserting thenozzle 2 in the bore 22.

The operation of the blowpipe, embodying the improved mixer, will beapparent from the foregoing description. The heating oxygen usuallysupplied to the mixer at a substantially higher pressure than theacetylene, is delivered from the pipe H to the passage 38 and dischargestherefrom at a substantial velocity across the lower end of the chamber25 into the outlet throat 23. This producesa suction and reduces thepressure in the chamber 25 by withdrawing gas from the latter, therebynot only assisting to draw acetylene from the pipe l8 into the chamber25 but at the same time drawing air through the passages 34 into thechamber 25 to dilute the acetylene. lhis mixture of acetylene and air isthen entrained and carried with the oxygen stream through the throat 23and the flaring passage H! where the several gases are thoroughly mixedbefore they are discharged from the passages 2! of the nozzle N. Thewalls of the relatively deep annular recess 2s compel an abrupt changein the direction of the inflowing air and, together with the sharpshoulders on the nozzle 25 and the narrowness of the chamber 25, producea turbulence in the air and acetylene which thoroughly mixes thesegases.

The size of the passage 30, the width of the chamber 25, and the sizeand number of the passages 34 are proportioned with respect to eachother to deliver a combustible mixture to the passages 2i whichisappropriate for the size of the latter and the preheating or welding tobe done. The blowpipe and mixer construction is particularlyadvantageous because both the nozzle N and the mixer nozzle 24 may beremoved readily and replaced by nozzles having larger or smallerpassages for operating upon heavier or lighter work.

While theinvention is illustrated as embodied in a cutting blowpipe, itwill be evident that it may be incorporated in other types of blowpipes,such as those used for welding. Clearly the oxygen supply and the fuelgas supply may be transposed, and air may be mixed first with the oxygeninstead of the fuel gas. Furthermore, under certain conditions theinvention may be applied in connection with the use of liquids, vaporsor pulverized solids. Various other changes may be made in the detailsof construction herein disclosed without departing from the principlesof the invention.

I claim:

1. A fluid mixing nozzle comprising a substantially cylindrical bodyportion; a threaded section intermediate the end sections of said bodyportion of greater diameter than said end sections; a conical head; anda neck of reduced section connecting said head integrally with said bodyportion; said nozzle having a central passage therein extendingsubstantially axially through a part of said body portion only, throughsaid neck and through said head; said nozzle having a passage betweenthe central passage therein and the unthreaded section of said bodyportion farthest from said head; and said nozzle having a passageextending longitudinally through said body portion only.

2. A fluid mixing nozzle comprising a substantially cylindrical bodyportion; a conical head; a neck of reduced section connecting said headintegrally with said body portion; a threaded section intermediate theend sections of said body portion of greater diameter than said endsections; said nozzle having a central passage therein extendingsubstantially axially through a part of said body portion only, throughsaid neck and through said head; said nozzle having a passage betweenthe central passage therein and the unthreaded section of said bodyportion farthest from said head, and an enlarged end integral with saidbody portion at the end thereof opposite the end to which said head isconnected, said enlarged end having plane faces parallel to thelongitu-dinal axis of said nozzle, said nozzle having a plurality ofpassages extending through said body portion only, substantially asdescribed.

3. A blowpipe comprising a body portion having a counterbored chamber;means for conducting different, gases to spaced points along saidcounterbored chamber; a nozzle Within said counterbore provided withmeans at a point between said spaced points adapted to secure it thereinand having reduced portions adjacent;

said securing means to form auxiliary chambers with said bore at saidpoints; a conduit adapted to connect one of said auxiliary chambers witha central duct within said nozzle; means for introducing a third gas to'said other auxiliary chamber comprising passages extending substantiallythroughout the length of said nozzle; and a bafiie between the exit ofsaid passages and the entrance of said other auxiliary chamber.

LLOYD W. YOUNG.

